The short answer: NVIDIA server cards (P40, P100, V100, P4, A2) have no fan of their own. You have to provide the airflow for them, whether in a server or in a desktop. Without it the card will overheat and throttle its clocks, and under sustained load it can shut itself down as a safety measure. This is not a fault in the card: it is the normal behaviour of hardware designed to work in an entirely different environment from a home PC case. Below I describe how I handle this in practice, so that you do not have to learn it by trial and error.
Why these cards are passive
When you pick up a Tesla P40 or V100 for the first time, the first reaction is often: "where is the fan?" There is none, because there never was one. Cards of this class were designed for rack servers, where all the airflow is forced by a row of fans in the front of the chassis: air enters on one side, passes through the card's heatsink (which is essentially a tunnel) and leaves on the other side, towards the power supplies and out of the chassis. The server room is designed around this airflow, and the card is just one element in the tunnel.
Put such a card into an ordinary mid-tower case, where the fans cool the whole case in a general, non-directional way, and the card's heatsink becomes a piece of metal that air barely gets through. Under full, sustained load (training, batch jobs or a busy inference server; an interactive chat loads the card only in bursts), the temperature rises within a few tens of seconds, the card starts cutting its clocks and, if the temperature keeps rising, it shuts down. I have verified this myself in a standalone test: a card without additional airflow on an open test bench can exceed 90°C in less than two minutes of gpu-burn.
This is the most common cause of disappointment for people buying such cards for the first time: not performance, not drivers, but the lack of cooling. It is worth sorting this out before the card even reaches your desk.
Rack or DIY: two approaches
You have two sensible options.
A server/rack chassis: if you have, or plan to have, a server that its vendor supports for passive GPUs of this class (a slot and riser for a full-length dual-slot card, a CPU 8-pin power lead and a GPU fan profile), the card goes into the existing air tunnel and works as the manufacturer intended. A generic 1U/2U server is not automatically such a chassis: many cannot fit a full-length dual-slot card, and the fan control often cannot read the temperature of a card it does not recognise, so it cools the slot area to a generic target rather than to what a 250 W passive card needs. This is the most "maintenance-free" solution: you do not have to design anything. The downside: noise (40-60mm server fans can be really loud at full speed) and size, since a rack does not sit quietly under a desk.
Adapting a desktop: if you want the card in an ordinary PC, you have to build a mini air tunnel around it yourself. This takes two components: a 3D-printed shroud (a cover) made for the card, plus a source of airflow with high static pressure, typically a 40mm server fan or a 97mm radial blower, or an ordinary fan (e.g. a Noctua) mounted on an adapter. The shroud directs the air from the fan along the card's heatsink, instead of letting it disperse throughout the case. This is the solution I reach for most often, because a desktop is quieter for everyday work and takes up less space than a rack.
There is a sizeable community around this: on r/homelab and similar places plenty of shroud designs for these cards circulate (many fit the PCIe P40, P100 and V100 alike), some of them available for download from Thingiverse-style sites. You do not have to design from scratch: it is worth looking for a ready-made file for your exact card model and just adjusting the mounting to your case.
Shroud + blower fan: how to choose them
A few things worth knowing before you start the printer:
- Matching the card model. The PCIe P40, P100 and V100 share the same full-height, full-length dual-slot format, and many shrouds are sold as fitting all three, but the fit at the end of the card is not always tight. Check that the design lists your exact card and that it is for the PCIe version, not SXM2, and test the fit before you print the final version.
- Direction of airflow. The blower or fan should push air through the heatsink along its fins, not perpendicular to them; otherwise most of the air will simply bypass the card's hot components.
- An airtight tunnel. If the shroud does not fit tightly against the card's housing, some of the air "escapes" sideways instead of passing through the heatsink. This is a common mistake with first prints: you sometimes need to seal the gaps with tape or a foam gasket.
- Fan power matched to the TDP. More on this below, as it depends heavily on the specific card model.
Low-profile cards are easier to cool
Not all of these passive cards pose the same problem. The TDP and form factor of a card make a huge difference to how much air you actually need to push through. Below I list the cards we most often source and have in our range; this is not an exhaustive list, and we source other accelerator models to order.
P40, P100, V100: these are cards of about 250W, dual-slot and full-height. A large heat output concentrated on a relatively small heatsink requires a really strong airflow: this is where a 40mm fan does real work, usually at high speed.
P4 (75W) and A2 (about 40–60W): low profile and much lower power draw. The difference here is noticeable: sometimes a modest blower is enough, or even well-arranged airflow in the case with a few additional fans, without extreme fan speeds. If you are building your first home lab and want to avoid 3D printing and choosing a blower, the P4 or A2 is a safer start as far as cooling is concerned: less can go wrong.
If you are aiming for more memory and performance and choosing the P40 or V100 32GB, plan proper airflow from the outset: this is not a card you will cool "somehow" with a random fan from a drawer. Check the length too: the PCIe card itself is 10.5 inches (about 267 mm), and the additional clearance needed for the shroud, fan and power cable depends on the design. Before printing, compare the dimensions of the complete assembly with your case's graphics card clearance.
While you are installing it: these larger cards are powered through an 8-pin EPS connector (not PCIe). It is worth checking this before buying a cable, because it is a common source of confusion. If your power supply has no spare CPU 8-pin lead, use an adapter from two PCIe 8-pin plugs to one CPU 8-pin, and never force a PCIe plug into the card: 12 V and ground sit on opposite sides in the two connectors. In addition, none of these cards has a video output: you need the CPU's integrated graphics or a second graphics card for display.
Monitoring and noise
Before you decide that the cooling works, check it with figures, not with a feeling that "it seems fine".
nvidia-smi (ideally in a loop, e.g. nvidia-smi -l 2) shows the card's temperature live. The goal is simple: under full, sustained load the temperature should stabilise well below the throttling threshold, not just at the start of the test, but after 15 minutes or more, once the heatsink has become saturated with heat. nvidia-smi -q -d TEMPERATURE shows your card's own slowdown and shutdown temperatures, and nvidia-smi -q -d PERFORMANCE shows whether the clocks are being cut for thermal reasons right now.
gpu-burn works well as a test load: it keeps the card at 100% for as long as you tell it to, so you can see whether your shroud and fan cope in a real scenario, not just during a short load spike. Two details matter: without an argument it runs for only 10 seconds, so give it the duration (e.g. ./gpu_burn 1200 for 20 minutes), and its default build targets compute capability 7.5, so build it for your card with a CUDA 12.x toolkit (make COMPUTE=61 for the P4 and P40, COMPUTE=60 for the P100, COMPUTE=70 for the V100).
There is a trade-off you cannot avoid: noise versus temperature. 40mm fans at high speed can be really loud; they are not a quiet component. PWM control or manually limiting the fan speed (if the temperatures allow it with a margin) helps you find the point at which the card is cool enough and you can still sit in the same room. For me this usually means a fan curve driven by the GPU temperature, so that the fan runs at full speed only under real load and is much quieter at idle. A motherboard fan header follows CPU or board sensors by default and does not see the card's temperature, so you need fan-control software that reads it (e.g. FanControl on Windows, or a small script on Linux that reads nvidia-smi and sets the PWM value), or a fixed speed that you have verified under sustained load.
If the fan is still too loud, lower the card's power limit: sudo nvidia-smi -pl <watts>, within the range shown by nvidia-smi -q -d POWER. The card then produces less heat at the cost of some performance; measure the difference on your own workload. The limit resets after a reboot, so set it from a startup script.
Common mistakes
The most common mistake I see (and one I once made myself) is relying on "the case has good airflow, so it will be enough somehow". The general airflow in a gaming case, even a good one, is not the same as a directional air tunnel through the card's heatsink. A card without a shroud, simply placed between other components, will in most cases overheat under full load, even if the case has several large fans.
Other typical slip-ups: a shroud that is not sealed against the card's housing (air escapes sideways), a fan chosen "by eye" without checking the card's TDP, and skipping a long load test. A short 30-second test will not show that the card keeps heating up after ten minutes of work.
FAQ
- Is an ordinary case fan enough for a Tesla P40?
- A case fan on its own very rarely is. Without a shroud directing the air along the card's heatsink, most of the airflow will bypass the area where it is actually hot.
- Can the P4 or A2 be cooled without printing a shroud?
- Sometimes yes, with well-arranged airflow in the case and the modest TDP of these cards, but it depends on the specific case and the ambient temperature. It is worth verifying with gpu-burn + nvidia-smi rather than assuming everything is fine.
- How loud is a 40mm fan at full speed?
- Loud: comparable to a server fan, because that is essentially what it is. PWM control and limiting the speed to the minimum sufficient under load make it considerably quieter.
- Will the card be damaged without cooling?
- It should not be: the protective mechanisms (throttling and, if the temperature keeps rising, shutdown) protect the card from damage. The problem is a practical one: the card simply stops working at full performance, or stops working altogether until it cools down.
- Where can I find an STL file for a shroud for my card model?
- It is worth searching home lab communities (r/homelab and similar, Thingiverse-style file repositories) for the exact model name: most popular cards (P40, P100, V100) already have ready-made, proven designs. If you are looking for a card that fits your cooling plan, from the low-profile P4 to the full-size V100, you can read our guide to used Tesla accelerators for AI and test your own setup with gpu-burn before putting the card under real load.